Researchers from the Scott Polar Research Institute at the University of Cambridge will be harnessing the power of robotics to explore the Weddell Sea underneath the Larsen Ice Shelves, in particular Larsen C.
The Larsen Ice Shelf covers 78,500 sq km of the earth’s sea—roughly the same size as Scotland (which is 80,077 sq km, fact fans!)
Both Larsen A and Larsen B have suffered catastrophic losses in the last 23 years and in 2017 a crack in the Larsen C Ice Shelf created one of the largest icebergs ever recorded, with a surface area of 5,800 sq km (around two and a half times the size of the Lake District).
Whilst scientists have been able to explore the top of the Larsen Ice Shelf fairly ‘easily’ (I use the word ‘easily’ here with a bit of caution, as I realise that exploring Antarctica is a bit harder than writing a blog post from my desk), nobody has yet to delve underneath the ice and use instruments to explore Larsen C.
So why does it matter?
Ice shelves buttress the interior of the Antarctic ice sheet and act to hold back the ice that flows from the interior to the edge. They are vulnerable as they can lose mass when icebergs are produced.
Because the ice shelves are floating, they have ocean water flowing underneath them, which can lead to significant melt rates at the base. The main aim of the expedition is to look at the stability of the floating ice shelves by getting underneath them.
Until now, there hasn’t been an effective method to track what’s happening under the ice. Step in, AUV!
What’s an AUV?
Autonomous underwater vehicles (AUVs) for the expedition have been provided by Ocean Infinity, the company currently searching the Southern Indian Ocean for the wreckage of Malaysian Airways Flight MH370, which disappeared in March 2014.
The AUVs will be used by researchers beneath the ice shelf, and these torpedo-like flying objects are equipped with instruments that will measure the salinity and temperature in the water. They can operate at a depth of 6,000 metres and are 6.2 metres long. These robotic instruments have been fitted with multi-beam instruments that go up and down and will be able to measure the roughness of the vast, underexplored cavities that lurk under the ice.
These cavities can be up to 100 km long and are hundreds of metres deep. The sea ice is notoriously difficult to work on and these cavities are so underexplored, we know more about the surface of Venus and the dark side of the moon (there’s a song in there, or possibly two). Luckily, the AUVs can travel quite far and have an operating time of up to 400 metres before they need to be recharged.
Multi-beam echosounders will be able to map the shape of the sea floor and the roughness of the upper part of the cavity where the ice meets the water. The roughness measure will be used by researchers for computer modelling and will give an indication of what the future holds for Antarctica, if the water keeps getting warmer.
The geophysical instruments will give images of the shape of the area, but the autonomous underwater vehicles have also been equipped with cameras.
Won’t it all just be a bit samey? All a bit… blue?
If you’re thinking that there’s not much to see under there, think again. Research will be taking place in the area where Shackleton’s Endurance sank in 1915. Frank Worsley (captain of Endurance) was sadly without his own AUV, so executed a series of sextant measurements that measured the exact position of Endurance.
Researchers from the Scott Polar Institute have used these measurements for their own research, so are hoping for greater success than previous plans to find Endurance.
If the new Weddell Sea Expedition 2019 succeeds, the ship will be listed as an historic monument, protected under international law.
Blimey, that’s exciting! Will it go on display?
Put simply, no. If the expedition finds the wreck it will be surveyed, photographed and filmed but no items will be removed.
Marine biologists may attempt to obtain scientific samples of deep-water marine species using the remotely operated vehicles, but no items will be removed from the wreckage.
It is not known if Celine Dion has committed to recording a commemorative single to mark the occasion, and Vanilla Ice has declined to comment.
Are there any other robots involved?
Coordinating with the underwater research and survey work, the fantastically named Professor Wolfgang Rack and his team from Gateway Antarctica at the University of Canterbury in New Zealand, will use specially-equipped, aerial drones to measure sea ice thickness and snow depth on the ice shelf.
The project will be used to develop and test the use of drones to gather and validate data, including satellite data. Drones can be deployed from sea ice or ships and can cover a large area quickly—a big advantage when surveying such a large area.
If you want to find out more about robots, then be sure to head on down to our Robots exhibition before it closes on Sunday 15 April!
Ocean Infinity AUV: Ocean Infinity, AUV Iris, fair usage